Field of the Invention
The apparatus relates to the field of electronic reproduction technology and relates to an apparatus for viewing originals in a flatbed scanner.
In an apparatus for scanning originals, such as pictures, graphics and texts, optoelectronically pixel by pixel and line by line, the originals to be scanned are converted into electric signals that are then further converted into digital data for processing in electronic reproduction technology. Such an apparatus is also denoted below as a scanner. For the case in which a flatbed scanner is involved, the originals are disposed on a flat copy holder, and an optoelectronic scanning unit scans the originals pixel by pixel and line by line, the copy holder and the scanning unit moving relative to one another. The scanning unit essentially has a light source for illuminating the original line by line, an optoelectronic transducer, for example, a photodiode row (CCD row), for converting the scanning light coming from the original into the image signals, as well as a scanning lens for projecting the original sharply onto the optoelectronic transducer and for adjusting the reproduction ratio in the case of originals of different size or for adjusting different scanning resolutions. Such a scanner is disclosed, for example, in German Published, Non-Prosecuted Patent Application DE 195 34 334.
There are flatbed scanners with a fixed copy holder and a scanning unit that moves along the copy holder in the secondary scanning direction, that is to say, perpendicular to the direction of the scanned line (the main scanning direction). Such a configuration is typical of what are called desktop scanners. However, there are also embodiments in which the copy holder moves along a fixed scanning unit.
To prepare the originals for scanning, the originals must be mounted on the copy holder, which is transparent as a rule. It is necessary for such a purpose for the copy holder to be illuminated using diffuse light, in order to be able to view the originals during mounting and to align them precisely. For flatbed scanners with a movable copy holder, this is achieved by virtue of the fact that the copy holder is positioned over a light box. No solutions yet exist for flatbed scanners with a fixed copy holder.